By Jon Herskovitz
AUSTIN, Texas, March 20 (Reuters) - A package bomb containing nails and shrapnel that was destined for an address in Austin, Texas, exploded at a FedEx Corp distribution center in San Antonio, injuring one employee, San Antonio fire officials said.
That blast came two days after the latest of four powerful homemade bombs set off in Austin this month that have killed two people and injured six more in what police warn appears to be the work of a serial bomber.
The package exploded shortly after midnight local time at a distribution facility in Schertz, Texas, outside of San Antonio, about 65 miles (105 km) south of Austin, the San Antonio Fire Department said on Twitter.
Agents from the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives were on the scene and investigating, fire officials said. They did not give further details of the address to which the package was bound.
Police did not immediately say if the explosion appeared to be linked to the four prior blasts. The first three were parcel bombs dropped off in front of homes on Austin's east side, with the fourth an apparent tripwire device that went off on the city's west side on Sunday.
Those four devices were similar in construction, suggesting they were the work of the same bomb maker, officials said.
FedEx officials could not be reached for immediate comment.
Additional reporting by Brendan O'Brien in Milwaukee Writing by Scott Malone Editing by Matthew Mpoke Bigg